Pulverulent material classifying means



May 12, 1953 G. NlEMlTZ PULVERULENT MATERIAL CLASSIFYING MEANS 3 Sheets-Sheet 1 Filed June 22, 1950 $1 QN & Z W 0 W W 5 y 2, 1953 G. NlEMlTZ 2;638,2l7

PULVERULENT MATERIAL CLASSIFYING MEANS Filed June 22, 1950 3 Sheets-Sheet 2 INVNTOR 6'. Aacmdz May 12, 1953 G. NIEMITZ 2,638,217

PULVERULENT MATERIAL CLASSIFYING MEANS Filed June 22, 1950 3 Sheets-Sheet 3 INVEIIVTOR' 6'. N4 emaz Patented May 12, 1953 PULVERULEN T MATERIAL CLAS SIFY IN G MEANS Gerhard Niemitz, Bronx, N. Y., assignor to Kennedy-Van Saun Mfg. & Eng. Corporation, New York, N. Y., a corporation of Delaware Application June 22, 1950, Serial No. 169,640

5 Claims.

classifier of this type which isreadily adjustable to obtain the desired quality of pulverulent material.

Another object of the invention is .to vary the velocity of air-borne pulverulent material entering a separating chamber of the classifier to provide one means of adjustment to obtain the desired quality of pulverulent material.

Another object of the invention is to interpose an adjustable balile or gate in the path of flow of the classified pulverulent material from the separating chamber to an outletin the classifier to provide another means of adjustment to obtain the desired quality of pulverulent material.

Another object of the invention is to introduce a controlled quantity of auxiliary fluid pressure or air stream to the residue discharge side of the separating chamber to return separated coarse particles of material to the classified pulverulent material to provide further means for obtaining the desired quality of pulverulent material.

'A further object of the invention is to provide the classifier with a separating chamber .comprising a housing having at the bottom an inlet for the air-borne pulverulent'material and an annular hopper encircling said inlet for the discharge of the residue of coarse particles of material. a vertical series of spaced baffles spaced from the side wall of the housing and in horizontal alignment with'the inlet, and an outlet at the top for the discharge of classified pulverulent material.

A further object of the invention is to provide a modified structure wherein reclassifying air is supplied to the classifier from the inlet for the air-borne pulverulent material and the quantity and velocity of the flow of said reclassifying air is regulated. 1

Other objects and advantages of the invention will be described hereinafter.

In the drawings accompanying and forming a part of this application,

Figure 1 is an elevational view of the classifier forming the embodiment of the invention.

Figure 2 is a top view of the classifier.

2 I Figure 3 is a fragmentary sectional view, on an enlarged scale, of a member adjustable toward and away from the pulverulent material inlet of the classifier to vary the velocity of discharge of said material into the separating chamber.

Figure 4 is an elevational sectional View, on an enlarged scale, taken substantially on the line i t of Figure 2 looking in the direction of the arrows.

Figure 5 is a fragmentary sectional view, on an enlarged scale, taken on the line 5-5 of Figure 4 looking in the direction of the arrows.

Figure 6 is a sectional view taken on the line E-6 of Figure 5 looking in the direction of the arrows.

Figure 7 is a view similar to Figure 4 showing a modified structure and arrangement of parts of the classifier wherein reclassifying air is supplied to the classifier from the inlet for the airborne pulverulent material and the quantity and velocity of the flow of said reclassifying air is regulated.

The embodiment of the invention illustrated in Figures 1 to 6, inclusive, of the accompanying drawings comprises a casing having at one end a cylindrical portion 8 partially closed at one end by an annular wall 9 and a conical shaped portion IEI at the opposite end of the casing. The casing is supported in vertical position with the cylindrical portion 8 uppermost and the conical portion l6 lowermost by four leg portions II extended laterally from the conical portion [0 for mounting on a suitable support, not shown.

The casing is connected in communication with the discharge of a pulverizing apparatus, not shown, to receive pulverulent material suspended in an air stream. This is accomplished by an inlet conduit I2 extending through the apex of the conical portion II! with the lower end of the conduit exterior of the conical portion and arranged with a flange I3 for connection with one end of a conveying conduit, not shown, connected at the opposite end to the discharge of the pulrerizing apparatus. The opposite end of the inlet conduit I2 terminates in the cylindrical casing portion 8 and is arranged with a flaring portion including a sectio'nM extending outwardly from the side wall of the conduit at an obtuse angle, a section I5 extending outwardly from the section Id at an obtuse angle, and a section is extending outwardly from the section I5 in a horizontal plane, as shown in Figure 4.

The air-borne pulverulent material is discharged from the flaring end portion I l-I6 of the inlet conduit I2 in a horizontalplane over the horizontal section Iii at an increased velocity. This is accomplished by a mushroom shaped member having a truncated conical shaped top H and truncated conical shaped bottom it arranged with an annular horizontal portion It of greater width than the horizontal section Hi. The mushroom member is adiustably mounted. to have vertical adjustment toward and away from the flaring discharge end i l-I6 of the conduit I2 by rods 2t fixed at the lower ends in sockets 2i secured to the horizontal bottom-pmtion. l9 and extended through the top conical portion IT. The upper ends of the rods 29 are arranged with a series of notches 22 and extended through. a circular plate 23 having an obliquely extending outlet 23 for the discharge of the classified pulverulent material and secured to the inner peripheral portion of the annular end wall 9, as shown in Figure 4.. The upper ends of the rods are adjustabiy suspended from the plate 23 by nuts 2% engaged with the notches 22 to abut the plate 23. The flaring sections M, !5-, it of the conduit l2 and the conical bottom I8 and horizontal portion 19 of the mushroom member form an annular flaring passage tapering outwardly to a horizontal discharge portion. Adjustm'ent of the mushroom member lT-lfi toward the discharge end i k-t6 of the conduit 12 will narrow said annular passage and increase the velocity of the air -borne material being discharged from. the conduit iii in an annular stream. The mushroom member ll! s is guided in its vertical adjustment by guide rods 26 secured at the lower end portions to the straight wall portion of the inlet conduit 12 and the upper portions extended through the conical bottom it, as shown in Figure 4. To prevent undue wear of the horizontal section It and horizontal por-. tion 19 by the aireborne pulverulent material, the horizontal section It is covered by a wearresisting surface 21 and the horizontal portion I9 is covered by a Wear-resisting surface of annular shape having a horizontal surface 23 at the inner peripheral portion and an outwardly declining surface 29 at the outer peripheral portion. The outwardly declining surface 29 coopcrates with the wear-resisting surface 2.! toform an outwardly restricted passage. The wear-resisting surface 21 is secured to the horizontal section It by screws 30 and the wear-resisting surface 23, 2% is secured to the horizontal portionis by bolts 3! screw threaded in said surface and supported in sockets 32 secured to the horizontal portion is and extended through the top conical portion I? of the mushroom member, as shown in Figures 3 and 4.

' The air-borne pulverulent material is discharged irom. the inlet conduit l2 into a separat ing chamber formed in the casing 8-40 by a housing including a vertical side wall 33 spaced from and supported by the-lower section of the cylindrical casing portion 3 by ribs 34. The up per portion of the housing is arranged with a wall portion 35 inwardly inclining from the upper edge of the side wall 33 to a second vertical wall portion 36 secured to the annular top casing wall 9 in encircling relation to the inlet end of the discharge outlet 24 and forming an outlet for the classified pulverulent material from the housing, as shown in Figure 4. The lower'portion of the housing is arranged with an annular hopper bottom formed by a wall 31 inwardly declining from the lower edge of the side wall 33 and a wall portion 38 outwardly declining from and supported by the horizontal section it of the conduit I2 and having the lower edge extending beyond and spaced from the lower edge of the wall portion 31 to form an annular outlet 39 for the discharge of the residue of coarse particles of the classified pulverulent material. The lower edge of the hopper bottom wall 38 and the inlet; conduit 22 are supported from the conical casing portion Hi by spaced arms 5-8, as shown in Figure 4.

Within the separating chamber formed by the housing 33 39,. baflies are provided for separating the coarse particles from the air-borne pulverulent material and directing the classified pulverulent material toward the outlet 2:- and the coarse particles. toward the hopper bottom outlet. 39 These bafiies comprise a vertical series of e uidistantl-y spaced annular slats ll supported by vertical ribs 42 secured to the inner faces of the housing wall portions 33, 35, 3? with the slats declining toward and spaced from the housing side wall: 33, as shown in Figures 4 to 6 inclusive. The aireborne classified material will. flow along the housing wall portions 33 and to the outlet 2 The residue coarse particles will be thrown out by kinetic energy of the air stream flowing through the annular space between the surfaces ZL-ZQ and deflected by the bailie' slats ti into the hopper bottom 31!, 38 and through the outlet 35 into the conical casing portion It. The residue of coarse particles in the conical casing portion H} is returned to the pulverizing apparatus to be again subjected to the pulverizing action through an outlet in the apex of said conical casing portion in the form of a chute 43 declining diagonally of the exterior of the inlet conduit l2 substantially in the plane of inclination of the wall of the casing portion H3 and. having an exterior tubular portion at arranged for connection with a return conduit, not shown, leading to the pulverizing apparatus. To facilitate the flow of the coarse particles down the chute 63', the casing portion H)- is provided with a diverging piece 45, as shown in Figure 4, to prevent accumulation of the residue of coarse mater-lat around the inlet conduit I2.

The degree of separation of the coarse particles. from the air-borne pulverulent material is primarily controlled by the adjustment of the mushroom member l?-! E, but is also controlled by two other means. One of said means cou prises a baffle in the form of a sleeve or an an nular gate is slidable within the housing wall portion 36 and adjustably supported by rods 41 secured; at the lower end portion to said sleeve 46' and the opposite end portions extended through the annular top wall 9 and arranged with a series of notches 48 for the engagement of nuts d9 abutting the outer surface of said annular wall 9. The baffle sleeve id is adjusted to position the lower portion thereof below the housing wall portion 3'6 in angular relation to the housing wall portion 35 and form an angular pocket with said wall portion 35, as shown at it in Figure 4, to catch any coarse particles being carried by the air-borne pulverulent material toward the outlet 24 and cause said particles to drop to the hopper bottom '3l--3 The area of the lower portion of the bafile sleeve 15 extending below the housing wall portion 38 will determine the amount of coarse particles removed from the air-borne pulverulent material.

The other means for controlling the degree of separation of the coarse particles from the airborne pulverulent material comprises introducing an auxiliary or reclassifying fluid pressure in the form of an air stream into the cylindrical casing portion 8through an inlet and said air stream flowing downwardly into the conical casing portion 10 and thence upwardly into the housing 33549 through the hopper outlet 39. The upward flow of the auxiliary air stream in the housing will lift a certain amount of fine and coarse particles into the main air stream of the classified pulverulent material flowing through the outlet 24. The flow of the auxiliary or reclassifying air stream. through the inlet 5! is controlled by suitable valve mechanism shown in: a general way at 52 in Figure 4. The amount of auxiliary air introduced into the casing will determine the quantity of coarse particles in the air-borne pulverulent material being discharged through the outlet 2-4. The auxiliary or reclassifying air is completely shut-oil from the casing when a maximum fineness of pulverulent material is desired.

' The outlet 24 is arranged with a flange 53 for connection with a conduit, not shown, leading to a place of use or storage of the classified pulverulent material.

54, 55 and 53 indicate inspection covers in the outlet 2t, conical casing portion In and inlet conduit l2, respectively, and 51 indicates poke holes.

Figure 7 shows a modified structure and arrangement of parts of the classifier wherein the separating chamber housing 33-39 and the auxiliary or reclassifying air inlet5l are omitted. The structure of the classifier casing is the same as the casing shown in Figures 1 to 6, inclusive,

and is indicated by the same reference numerals 3 3 to ll, inclusive. The inlet conduit for the airborne pulverulent material in the Figure '7 disclosure comprises a straight end section 58 having a flange 59 at the lower end for connection with one end of the conveying conduit connected at the opposite end to the discharge of the pulverizing apparatus. The opposite end of the inlet conduit se-ction58 is extended into the conical casing portion ill and is arranged with a liaring portion 69 having a ring SI of wear-resisting material on the inner surface at the end thereof.

The lower end of the opposite end section 62 of the inlet conduit is arranged with a flaring end portion having an inner wear-resisting surface and spaced from the flaring portion 60, as shown at 53. The upper end of the inlet conduit section 62 is provided with a daring portion 64 having a horizontal flange 65. The horizontal flange 65 is arranged with a wear-resisting surface 66 secured thereto. A shell having converging wall portions 8'! and 68 connected together by a vertical portion '69 is connected to the inlet conduit section 52 by wall portion 61 being united to the horiaontal flange 55 and the wall portion (58 having a horizontal wall section it united to the section 62. The wall portion til and the conical casing portion ii] form an annular passage for reclassifying air discharged from the space between the inlet conduit sections 58 and 62. i

The quantity of said reclassifying air is regulated by a valve in the form of a collar having a conical wall portion ll extending in the angle of inclination of the flaring end portion 63" and a vertical portion 12 arranged with a wear-resisting ring l3 adapted to form with the wear-resisting ring El an adjustable annular discharge opening for the reclassifying air. The collar '1 ll3 is adjustably supported in the conical casing portion Ill by an arm 14 secured at one end to the Wall portion H and having a sleeve *1 5 at the opposite end secured on one end of an 6 adjusting screw 16. The'adjusting screw it is adjustably supported by a bracket 71 secured to the exterior of the conical casing portion IB and the screw 16 is extended through a boss it in the conical casing portion Ill. The screw it is're tained in adjusted position by lock nuts 19. Adjustment of the screw it in an upward direction moves the collar valve 'ill3 from the wear-re sisting ring 6! and permit a greater amount of air to be discharged from the inlet conduit section 58 into the annular passage formed by the conical casing portion IE! and shell wall portion 68. Adjustment of the screw it in a downward direction moves the collar valve H -l3 toward the wear-resisting ring and decreases the quantity'of air flowing from the inlet conduit section 58 into the annular passage formed by the conical casing portion It and shell wall portion lit. The velocity of the flow of reclassiiying air through the annular passage formed by the conical casing portion it and shell wall portion68 is regulated by another collar valve ill of conical shape having an angle of inclination corresponding to the inclination of the conical casing portion ID. The collar valve 83 is adjustab-ly mounted in the outlet portion of said annular passage by an adjusting screw 8| adjustably sup ported by a bracket 82 secured to the exterior of the conical casing portion It. The adjusting.

screw 8! is extended through a boss 83 in the conical casin portion iii and secured at the inner end in a boss 84 arranged in the collar valve 88. Adjustment of the screw Bl in an upward directionmoves the collar valve t6 toward the shell 61-10 and increases the velocity of the flow of reclassifying air through said outlet portion of the annular passage formed by the conical casing portion ill and shell wall portion lit. Adjustment of the screw 81 in a downward direction moves the collar valve fill from the shell Bl-lfl and decreases the velocity of the flow of reclassifying air through said outlet portion. The vertical Wall portion 59 of the shell is protected from abrasive action of the reclassifying air-by a \vear-1'esisting.band 85 secured to the exterior surface of said wall portion lid. The small area ofthe discharge opening formed by the wear-resisting rings all and it will permit only passage of fine particles of pulverulent material with the ,air being dis-charged. therethrough, so that the principal element flowing through the annular passage formed by the conical casing portion Ill and shell wall portion til is air.

The bulk of. the air-borne pulverulent material in the inlet conduit 58-65 is discharged therefrom through an adjustable annular opening formed between the wear-resisting surface 66 and a wear-resisting ring 86 secured to the peripheral portion of the bottom wall of a mushroom shaped member 81. The mushroom member 81 is adjustably mounted in the casing 8-40 to vary the size of the opening by rods 88 secured at one end to the member 8? and adjustably suspended from an annular plate 89 by nuts 90 engaged on the rods and abutting said plate 89. The plate 89 is secured to the inner peripheral portion of the annular end wall 9 of the casing. .The wear-resisting ring 86 and rods 88 are similar in structure and attachment to the wear-resisting surface 28, 29 and rods 29) described hereinbefore. The mushroom member 81 is guided in a vertical direction by rods 9H .secured to the inlet conduit section 62 and extended through the bottomof the member 8T.

1 Aoiustment or the member 81- toward and: away fromi the flaring, end portion M or the inlet, conduit -espectively increases and decreases the velocity of the How of air-borne pulverulent material. from the inlet conduit toward a vertical series, of cauid s a tlv spaced a nular bafile slats 8:21 moun ed in spaced el ion to th yli dric casing. portion & bit vertical ribs at, The baflle slats 92; function. in the same manner as the ballle slats M. The recl'assif ying air flowing from the annular passage tanned by the conical casing portion Ill and shell wall portion 68 will flow along the. Shell wall portion 6'! and act on the ai-rborne pulverulent materialv flowing from the denine terme bv t e e rs s n fines 6i,

8,5 in. the same manner as the auxiliary air introduced into the casing through inlet of the Figure 4i structure.

The mushroom members Il'--l9 and 8! are adapted to be lifted ffrom the casing B-.l9'by suitable lift mechanism attached to an eye 94 secured to said members.

The classified pulverulent material in the Fig ure'l structure flows from the baflle 92 to a. discharge outlet 95 in the plate 99 arranged with a flange 96 for connection with a discharge condu-it, not shown, leading to a place of use or storage of the classified pulverulent material. The discharge outlet 95 is arranged with an adjustable baffle to control the coarseness of the pulverulent; material being discharged therethrough. Said adjustable bafile comprises an annular wall 91 secured to and depending from the casing wall 9 and a sleeve or annular gate 98' slidable on the wall 91 and adjustably supported by rods 99 secured at one end to the gate 98 and adjustably mounted in the annular wall 9 in. the same manner as rods 41. The adjustment of the gate 98 will obtain thev same results obtained by the adjustment of the gate 46.

In the Figure I structure, the residue of coarse particles separated by the. bafile 92 drop along the wall of the casing 8-40 between the valve 89 and the conical casing portion In onto a chute I09 similar in structure to the chute 43 of the Figure l structure for the return of said residue to the pulverizing apparatus as hereinbefore described.

the Figure '7 structure, the separating chamber is formed in the cylindrical casing portion a by the wall of said casing portion forming one side of the chamber and the other side of the chamber being formed by the shell wall 6'! and the conical side of the mushroom member g'l. The bottom of said separating chamber is defined by the collar valve Bil and the top of the chamber is formed by the an ular casing wall 9 a d he baffle m m ers Having thus described my invention, I claim:

1,, In pulverulent material classifying means, vertically disposed casing, an inlet conduit for air-borne pulverulent material extended through th W em i he Casing an t rmi ati at an intermediate portion of the casing, a member adjustably mounted in the casing to have adjust ment toward and away irom the terminating end of the inlet conduit and arranged to iorm with said terminating end an annular discharge openez ztending in, a horizontal plane, the adjustment of said member varying'the width of said opening and the fineness of the material discharges. from the casing, a vertical series of annular slats. spaced irom each other and mounted within the casing. in spaced horizontal alignment With said a nu r schar e op n a tl t n h ottom o th c e or the residue of c ar p ti e at he si e h are he. ea es ing the adjustable member and spaced from the side wall of the casing, the annular discharge opening and slats within the casing and having a center opening in t e upper portion commur nicating with the outlet in the top of the casing and-an annular opening in the lower portion com municating with the bottom of the casing, and a valve controlled auxiliary fluid pressure imet in the side wall of the casing; in communication with the space between the housing and casing to control the quantity of coarse: particles of material discharged through the, outlet in the top Df the casing.

2. In pulverulent material classifying means, a vertically disposed casing having a cylindrical upper portion arranged with an outlet for classilied pulverulent material and a conical lower pore tion arranged. with an outlet for residue of CQarse particles, an inlet conduit for air-borne pulyerulent material extending through and supported by the conical casing portion and terminating within the cylindrical casing portion, a housing having an annular hopper bottom arranged with a discharge opening in, the apex thereof and the inner side wall of said" hopper bottom secured to the terminating end of the inlet conduit and the outer side wall of the hopper bottom spaced from the wall of the conical casing portion, a vertical wall extending upwardly from the outer side wall of the hopper bottom in spaced relation to and supported by the side wall of the cylindrical portion and a wall portion inclining inwardly from the vertical side wall to a second vertical wall portion secured to the end wall of the cylindrical casing portion and forming an open top to the housing communicating with the outlet for the classified pulvcrulent material, baiiles mounted on-the inner face oi the first side wall of the housing in spaced relation thereto, and a member adjustably suspended from the end wall of the cylindrical casing portion for adjustment toward and away from the terminating end of the inlet conduit to form therewith an annular opening for the discharge of the air-borne pulverulent material at a high velocity in a horizontal plane into impact with the baflles, whereby the coarse particles of material are separated from the air-borne pulverulent material and the air-borne material directed by the bafiles and the inclining wall portion of the housing to flow towarol the outlet in the cylindrical casin portion and the coarse particles of material directed by the bames to gravitate to the hopper bottom and through the discharge opening therein to the conical casing portion and the outlet therein.

3. in pulverulent material classifying means as claimed in claim 2, a sleeve shaped baffle ad.- justably supported to have sliding movement within the second vertical wall portion vof the housing and extend in angular relation to the inclining wall portion of the housing to control the quantity of coarse particles in the air-borne pulverulent material flowing to the outlet in the cylindrical casing portion.

4. In pulverulent material classifying means, a vertically disposed casing having outlets at the top and bottom and an annular passage in an intermediate portion thereof, an inlet conduit for air-borne p-ulverulent material extended through the bottom of the casing and terminating above the annular passage in the casing and having an annular opening in an intermediate portion thereof below the annular passage in the casing for the discharge of reclassifying air into said annular passage, a member 'adjustably supported by the casing to have adjustment toward and away from the terminating end of the conduit and form with said terminating end an adjust-- able annular discharge opening extending in a horizontal plane for the discharge of the bulk of the air-borne pulverulent material delivered by the conduit, a member adjustahly supported by the casing to have adjustment toward and away from the annular opening in the conduit to regulate the quantity of reclassifying air from the conduit to the annular passage, and annular baffies mounted in the casing in spaced horizontal alignment with said adjustable annular discharge opening and above the outlet portion of the annular passage to separate the coarse particles of material from the air-borne pulverulent material and direct the flow of air-borne pulverulent material to the outlet in the top of the casing and direct the coarse particles of material to the outlet in the bottom of the casing, and the reclassifying air flowing from the annular passage controlling the quantity of coarse particles of material discharged through the outlet in the top of the casing.

5. In pulverulentmaterial classifying means as claimed in claim 4, a valve member adjustably supported by the casing in the outlet portion of the annular passage to regulate the velocity of the flow of reclassifying air from said annular passage.

GERHARD NIEMITZ.

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